Reenable iOS tests, default hardware/iOS version only for now

Use of the -destination argument to either xcodebuild or xctool
fails on Travis.

Refs #1452

scripts/ios/run.sh

@@ -28,5 +28,5 @@ if [[ ${PUBLISH_PLATFORM} = 'ios' ]]; then
 else
     # build & test iOS
     mapbox_time "run_ios_tests" \
-    make ipackage-sim
+    make itest
 fi

scripts/ios/test.sh

@@ -4,13 +4,8 @@ set -e
 set -o pipefail
 set -u
 
-xcodebuild \
+xctool \
     -project ./test/ios/ios-tests.xcodeproj \
     -scheme 'Mapbox GL Tests' \
-    -sdk iphonesimulator \
-    -destination 'platform=iOS Simulator,name=iPhone 5s,OS=7.1' \
-    -destination 'platform=iOS Simulator,name=iPhone 5s,OS=latest' \
-    -destination 'platform=iOS Simulator,name=iPad 2,OS=7.1' \
-    -destination 'platform=iOS Simulator,name=iPad 2,OS=latest' \
-    test \
-    | xcpretty
+    -sdk iphonesimulator8.3 \
+    test